The present invention relates to electronic control systems and displays and more particularly, to a system and technique for dynamically developing an electronic display format.
In various technologies, conventional electro-mechanical instruments are rapidly being replaced by digital controls and color cathode ray tube display devices. This is particularly true in aircraft monitoring and display systems wherein aircraft indicators are being replaced with compact digital display systems. Although digital techniques may easily be used to convert analog signals used to control meter movements into digital signals which provide numerical readouts of those analog values, an even more significant change has been in the use of stroke-written cathode ray tube technology to display numerical as well as visual graphics and symbols representing aircraft parameters. Thus, for example, conventional Attitude Director Indicators (ADI), Horizontal Situation Indicators (HSI), and other electro-mechanical flight instruments are being replaced with visual displays fashioned on multicolor cathode ray tube (CRT) to produce similar visual images.
In many instances, the new technology CRT display systems are very similar to that of the electro-mechanical instrument displays. However, the versatility of the CRT technology in allowing easily changed numeral and visual data to be displayed simultaneously, has led to a wide variety of proposed changes in display concepts. Thus, may individual displays are now being replaced with single displays and various functions previously performed by mechanical meter movements can now be easily displayed by the use of graphics and symbology on the face of a CRT. The CRT technology likewise allows various individual functions to be selectively multiplexed so that using only one CRT, a multiplicity of modes may be selected, each providing appropriate visual displays indicative of that mode of operation.
In the evolution of the above-mentioned CRT technology, various graphics, symbols, colors, and combinations of alpha-numeric and visual data are proposed during the development of a particular instrument. During that development cycle, many possible alternatives may be suggested, but there is still a problem in selecting that one which is most advantageous in use. Because of the inherent flexibility and versatility of the cathode ray tube, there is a tendency to have cluttered displays containing more information than is necessary or capable of being perceived in the operational environment. Accordingly, in order to determine which display format is acceptable, prior art practices have basically employed hit-and-miss construction techniques for forming a particular instrument display format. Thus, an instrument display having selected characteristics would first be produced in prototype form and then analyzed to determine its effectiveness. Thereafter, it would be redesigned and modified until a final acceptable product had been achieved.
As will be apparent from the above, even with the improved technology there remains significant trial-and-error in the production of electronic instrument displays using the prior art techniques. As a result, only a limited number of visual display formats are ususally considered even in the development of a CRT display. This experimentation and development is essentially confined to the use of graphics, symbols and alpha-numerics to form visual displays similar to that used in prior art electro-mechanical instruments. In addition to the significant design effort required using prior art practices, the regulating agencies also tend to discourage innovative changes in instrument displays since they are reluctant to certify instruments when their operation and visual acceptability cannot be analyzed before final production. As a result, any production of new displays which vary greatly from the norm is normally expensive and time consuming.
As advances in technology lead to the development and initiation of many different types of aircraft, there is a severe need for systems and techniques capable of producing and quickly evaluating electronic displays. The invention has therefore been developed to overcome the specific shortcomings of the above known and similar techniques and to provide an improved apparatus for aiding the development and certification of aircraft flight instruments and displays.